Commpilot, will the occupant of the aircraft be an instructor?
Aviator and other US FTOs have APP schemes were people gain their multi IRs, Commercials and CFI ratings then go on to build hours as saftey pilots. If one of those is alongside you and you're logging for JAR purposes, that's makes you P u/t I'm afraid. You may be the 'sole manipulator of the controls' but PIC is Pilot In Command, not Pilot In Control...